43. What is the difference between an independent and a dependant variable? (4)

44. How is a co-relational relationship different from a causal relationship between two or more variables? Give an example(s). (4)

45. We can only ascertain the causal relationship between variables if there is evidence of a causal effect. What is the causal effect? (give three points that signify the effect) (4)

46. It is also necessary to establish whether there is a (a) necessary and (b) sufficient cause to understand causality between variables. What is a

i. Necessary cause (3)

ii. Sufficient cause (3)

47. Every variable must have 2 key qualities - its attributes must be

i. exhaustive, and

ii. mutually exclusive

What do these terms mean? (4)